Are you an attorney or consultant struggling to accurately keep track of the time you’ve spent on various projects for billing clients?

On-Core’s Time Master app uses timers to precisely clock how much you should charge for your efforts. With the app’s optional billing module, you can even create a PDF invoice to send to clients.

To create a new entry, just select your client or add a new one and enter the project or task. Set your start date and time and how many hours and minutes you plan to work. Enter the rate you’re charging, which you can change for certain clients.

When you’re ready to start working, just tap on the time on the time entries page and the timer will start running. Tap on the time again when you stop working and the app will show you how long you’ve worked and how much you’ve billed.

Time Master is available for the iPhone, iPad and iPod Touch and costs $9.99.